New disturbance at Trump rally as crucial Republican contests near

DAYTON, Ohio, March 12 (Reuters) - Secret Service officers
rushed on stage to protect U.S. Republican presidential
front-runner Donald Trump during a disturbance at a rally on
Saturday, a day after rowdy protests shut down his event in
Chicago.

Trump briefly ducked at the podium and four Secret Service
members scrambled to surround him after a man charged the stage
at Dayton International Airport in Ohio.

Officers then grabbed the man, dressed in a black T-shirt
and jeans, before he was able to reach the stage and hauled him
away.

"I was ready. I don't know if I would have done well but I
would have been out there fighting, folks," Trump told a rally
later in the day. He said the man "was looking to do harm."

The incident further increased tension after Trump's Chicago
rally was scrapped amid chaotic scenes on Friday.

Trump's Republican rivals hurled scorn at the New York
billionaire, saying he helped create the nervous atmosphere that
is now sweeping the race for the White House with his fiery
rhetoric.

Trump blamed supporters of Democratic candidate Bernie
Sanders for the incidents in Chicago, where scuffles broke out
between protesters and backers of the real estate magnate. He
called the U.S. senator from Vermont "our communist friend."

The scenes in Chicago followed a series of recent incidents
of violence at Trump rallies, in which protesters and
journalists have been punched, tackled and hustled out of
venues, raising concerns about degrading security leading into
the Nov. 8 election.

"All of a sudden a planned attack just came out of nowhere,"
Trump said in Dayton, describing the events in Chicago. He
called the protest leaders there "professional people".

Sanders, a U.S. Senator from Vermont, hit back.

"As is the case virtually every day, Donald Trump is showing
the American people that he is a pathological liar. Obviously,
while I appreciate that we had supporters at Trump's rally in
Chicago, our campaign did not organize the protests."

President Barack Obama told a fundraising event in Dallas
that political leaders "should be trying to bring us together
and not turning us against one another."

Democratic front-runner Hillary Clinton drew criticism for
releasing an initial statement that did not mention Trump by
name and tied violent campaign events to a shooting in a South
Carolina black church last year that left 9 people dead.

While campaigning in St. Louis, Missouri, on Saturday,
Clinton criticized Trump directly for "ugly, divisive rhetoric"
that encourages aggression and violence.

CRUCIAL PRIMARIES

The months-long Republican race may be coming to a head at
nominating contests on Tuesday where Trump is seeking victories
that might give him an almost insurmountable lead for the
nomination.

Primaries in Florida and Ohio will be particularly important
since they are winner-take-all states, where all Republican
delegates are given to the winner of the popular vote instead of
being awarded proportionally.

It will be a make-or-break day for Republican candidates
John Kasich, the governor of Ohio, and U.S. Senator Marco Rubio
of Florida, who both must win their home states to forge a
credible path forward.

Trump has drawn fervent support as well as criticism for his
calls to build a wall along the U.S.-Mexico border and to impose
a temporary ban on Muslims entering the country.

His rallies often attract small groups of protesters, but
Friday's was the first at which there may have been as many
protesters as supporters.

At an event in Kansas City on Saturday, Trump urged police
to arrest people who disrupt his events.

"They'll have to explain to Mom and Dad why they have a
police record and why they can't get a job. And you know what?
I'm going to start pressing charges against all these people and
then we won't have a problem," he said to cheers.

Outside the rally, police broke up confrontations between
Trump supporters and protesters who shouted, "Shut it down!"

Police on horseback and riot gear briefly moved into a crowd
of protesters and officers used what appeared to be pepper spray
against demonstrators for a few seconds.

Rubio, who according to the New York Times slightly edged
out Kasich on Saturday to win the Washington D.C. primary with
37 percent of the vote, bemoaned the state of the presidential
race during an event in Florida, saying it had "become reality
television."

"Last night in Chicago, we saw images that make America look
like a Third World country," Rubio said, reminding supporters
the stakes on Tuesday are high.

Kasich told journalists before a campaign event in
Cincinnati, Ohio, that Trump had created a "toxic environment."

Republican candidate U.S. Senator Ted Cruz of Texas called
the Chicago incidents "sad."

Vanderbilt University political scientist John Geer said
that the tension on display at Trump's events are a proxy for
what is going on in the electorate writ large.

"People have strong reactions to Donald Trump," Geer said.
"They are playing out in the voting booth and they are also
playing out at these events."

Geer said the Chicago cancellation would likely embolden
Trump's supporters - an idea floated by Trump in several
television interviews.

Clinton picked up four delegates in the Northern Mariana
Islands' Democratic primary on Saturday, to Sanders' two.

On the Republican side, Cruz won around two-thirds of the
votes in Wyoming's Republican nominating contest but because of
the state's unusual rules it is not clear how many Wyoming
delegates will go his way at the Republican Convention in July.
(Additional reporting by Alex Dobuzinskis in Los Angeles, Kevin
Murphy in Kansas City, Idrees Ali and Amanda Becker in
Washington.; Editing by Alistair Bell and Sandra Maler)